If it's SPICE world then this setup may be a bit more helpful: a current source directly in the base of the transistor, with either the emitter (for determining \$C_{je}\$), or the collector (for \$C_{jc}\$) grounded, and the results come by reading the voltage. Or a voltage source and read the current. Here's an example with 2N2222, with the emitter grounded:

You know that \$R_b\$ is in series with \$R_e\$ and \$C_{je}\$. This is a series RC which, when fed with a constant current source, becomes a PI compensator, so you know you have a corner frequency given by \$f_c = (R_b + R_e)C_{je}\$. Until \$f_c\$ it's an integrator response, afterwards it's flat. The flat portion tells you the DC voltage given by \$R_b + R_e = 10.2\textrm{V}\$ (the 1st cursor), and \$f_c \approx 624\textrm{MHz}\$ is given by reading the phase of \$-45^\textrm{o}\$ (1st order RC, cursor 2, Y-axis set to linear, for easier reading). Since the current source uses AC 1
, that means that the input is unity, so there's no need to divide the voltage by the input current.
$$C_{je}=\frac{1}{2\pi\cdot 10.2\Omega\cdot 624\textrm{MHz}}=25\textrm{pF}$$
Similar for \$C_{jc}\$. The pleasure of finding out the capacitance for 2N3904 belongs to you. BTW, maybe you know, pressing Ctrl+C
when a transistor model is selected in the list, will copy the .model
definition to the clipboard. That's how it's pasted in the schematic.
Using this method it's easy to determine \$R_b\$, \$R_c\$, and \$R_e\$, individually, by simply reading the flat portion of the voltage from the floating pin (V(y)
). Since it's a current source of \$1\textrm{A}\$, the voltage at the floating pin will be \$R_e\$, in volts (for grounded emitter), and the difference will be \$R_b\$ (V(x,y)
). Similar for \$R_c\$. This works better in .AC
than .TRAN
:

Note the use of node labels, which makes life easier not only for me, but also for people reading the schematic. That's what I meant in the comment. Plus, the default names for nodes do change as soon as LTspice deems necessary, and it's not a bad habit to form.
V(n005)
), then it is (almost) mandatory you manually rename the nodes. This is because, as you add more nodes, their names are automatically re-ordered, so what you think asV(n005)
, it may no longer be the case after any operation involving a modification of the nodes in the schematic. It also makes debugging easier, not to mention it makes it more clear for people reading your schematic which nodes you're referring to. \$\endgroup\$